Picolylamine resins

ABSTRACT

The present application relates to novel gel-type or macroporous picolylamine resins which are based on at least one monovinylaromatic compound and at least one polyvinylaromatic compound and/or a (meth)acrylic compound and contain tertiary nitrogen atoms in structures of the general formula (I) 
                         
as functional group, where
     R 1  is an optionally substituted radical from the group consisting of picolyl, methylquinoline and methylpiperidine, R 2  is —CH 2 —S—CH 2 COOR 3  or —CH 2 —S—C 1 -C 4 -alkyl or —CH 2 —S—CH 2 CH(NH 2 )COOR 3  or —CH 2 —S—CH 2 —CH(OH)—CH 2 (OH) or   

                         
or derivatives thereof or —C═S(NH 2 ),
     R 3  is a radical from the group consisting of H, Na and K, m is an integer from 1 to 4, n and p are each, independently of one another, a number in the range from 0.1 to 1.9 and the sum of n and p is 2 and M is the polymer matrix, a process for preparing them and their uses, in particular the use in hydrometallurgy and electroplating.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

The present patent application claims the right of priority under 35U.S.C. §119 (a)-(d) and 35 U.S.C. §365 of International Application No.PCT/EP2009/052334, filed 27 Feb. 2009, which is entitled to the right ofpriority of German Patent Application No. DE 102008012223.8 filed on 3Mar. 2008.

The present invention relates to novel picolylamine resins containingtertiary nitrogen atoms in structures of the general formula (I)

as functional group, where

R₁ is an optionally substituted radical from the group consisting ofpicolyl, methylquinoline and methylpiperidine, R₂ is a radical—CH₂P(O)(OR₃)₂ or —CH₂—S—CH₂COOR₃ or —CH₂—S—C₁-C₄-alkyl or—CH₂—S—CH₂CH(NH₂)COOR₃ or —CH₂—S—CH₂—CH(OH)—CH₂(OH) or

or derivatives thereof or —C═S(NH₂),

R₃ is a radical from the group consisting of H, Na and K, m is aninteger from 1 to 4, n and p are each, independently of one another, anumber in the range from 0.1 to 1.9 and the sum of n and p is 2 and M isthe polymer matrix, a process for preparing them and their uses, inparticular the use in hydrometallurgy and electroplating.

Chelating exchangers are nowadays used for many separation problems inindustry. Thus, they are used, inter alia, for removing anions fromaqueous or organic solutions, for removing anions from condensates, forremoving colour particles from aqueous or organic solutions or forremoving organic components from aqueous solutions, for example humicacids from surface water.

Furthermore, chelating exchangers can be used for the purification andtreatment of water in the chemical industry and electronics industry, inparticular for producing high-purity water or else in combination withgel-type and/or macroporous cation exchangers for deionizing aqueoussolutions and/or condensates.

Beyond these known applications, there is a desire to open up new fieldsof application for ion exchangers which are not suitable for thechelating exchangers known at present or in which such chelatingexchangers show an insufficient adsorption capacity.

There is therefore a need for novel chelating exchangers based on atleast one monovinylaromatic compound and at least one polyvinylaromaticcompound as crosslinker, which display improved selectivity for ions tobe separated off and also a high mechanical and osmotic stability incolumn processes compared to the ion exchangers according to the priorart.

U.S. Pat. No. 4,098,867, Table 1, describes a heterodisperse, gel-typechelating resin which bears tertiary nitrogen atoms in a structuralelement of the formula (II)

as functional group, where

-   M is the resin matrix,-   Q if a —CH₂— radical,-   Y can be H or C₁-C₄-alkyl and-   R is —CH₂—COOH.

Chelating resins of this prior art are prepared by halomethylation of abead polymer which is based on styrene and divinylbenzene and isobtained by suspension polymerization (chloromethylation process),where, on average, from 0.1 to 1.0 halomethyl group per aromatic ring isintroduced as reactive group for the addition of the aminomethylpyridinechelating function.

In practice, the use of such a resin according to U.S. Pat. No.4,098,867 has shown that use in metallurgy, preferably in the winning ofmetals of value, in particular copper, no longer meets present-daydemands.

It was an object of the present invention to provide novel picolylamineresins having the above-described requirement profile for the removal ofsubstances, preferably cations, in particular copper, and polyvalentanions, from liquids, preferably aqueous media or gases, and to providea process for preparing them. For the purposes of the present invention,substances to be removed additionally include, in particular, metals ofvalue.

This object is achieved by, and the present invention accordinglyprovides, novel, gel-type or macroporous picolylamine resins which arebased on at least one monovinylaromatic compound and at least onepolyvinylaromatic compound and/or a (meth)acrylic compound and containtertiary nitrogen atoms in structures of the general formula (I)

as functional group, where

R₁ is an optionally substituted radical from the group consisting ofpicolyl, methylquinoline and methylpiperidine, R₂ is a radical—CH₂P(O)(OR₃)₂ or —CH₂—S—CH₂COOR₃ or —CH₂—S—C₁-C₄-alkyl or—CH₂—S—CH₂CH(NH₂)COOR₃ or —CH₂—S—CH₂—CH(OH)—CH₂(OH) or

or derivatives thereof or —C═S(NH₂),

R₃ is a radical from the group consisting of H, Na and K, m is aninteger from 1 to 4, n and p are each, independently of one another, anumber in the range from 0.1 to 1.9 and the sum of n and p is 2 and M isthe polymer matrix.

In the interests of clarity, it may be pointed out that any combinationsof definitions and parameters mentioned below in general terms or inpreferred ranges are encompassed by the scope of the invention.

In a preferred embodiment, n is from 0.5 to 1.5 and p is from 1.5 to0.5, with the sum of n+p always being 2.

The picolylamine resins of the invention surprisingly display asignificantly better absorption capacity for copper than the chelatingresins of U.S. Pat. No. 4,098,867.

It may be presumed from studies in the context of the present inventionthat the halomethylation process described in U.S. Pat. No. 4,098,867for introducing the functional group for the purpose of preparing theheterodisperse chelating exchanger appears to lead to a limitation ofthe degree of functionalization. Thus, after-crosslinking appears tooccur in the halomethylation according to U.S. Pat. No. 4,098,867 andlead to a loss of halomethyl groups. Owing to the resulting loss ofhalomethyl groups which can be reacted with aminomethylpyridines, theresulting chelating resins have fewer functional groups available forthe winning of metals of value, which considerably restricts the use ofthe resins in metallurgy. In addition, it has been found that theprocess according to the prior art is restricted in terms ofvariability. The preparation of picolylamine resins in a wide range ofamounts of picolyl groups and additional chelating groups having a highdegree of functionalization, high kinetics and a high capacity is notpossible according to U.S. Pat. No. 4,098,867 but is possible by theprocess of the present invention.

The present application therefore also provides a process for preparingthese novel macroporous or gel-type picolylamine resins bearing tertiarynitrogen atoms in structures of the general formula (I)

as functional group,

-   where R₁, R₂, R₃, M, m, n and p are as defined above, characterized    in that-   a) monomer droplets of a mixture of a monovinylaromatic compound, a    polyvinylaromatic compound and/or a (meth)acrylic compound, an    initiator or an initiator combination and optionally a porogen are    reacted to form a crosslinked bead polymer,-   b) the bead polymer obtained is functionalized with primary amino    groups,-   c) the functionalized bead polymer containing amine groups is    reacted with halomethyl nitrogen heterocycles to form bead polymers    which have basic, anion-exchanging groups and contain methyl    nitrogen heterocycles and-   d) the bead polymer containing methyl nitrogen heterocycles obtained    in process step c) is reacted with phosphorus-hydrogen-acidic    compounds or sulphur-hydrogen-acidic compounds or else C—H-acidic    hydroxyquinone derivatives to form the picolylamine resin of the    invention having additional chelating groups, as a result of which    this acquires —CH₂P(O)(OR₃)₂ or —CH₂—S—CH₂COOR₃ or    —CH₂—S—C₁-C₄-alkyl or —CH₂—S—CH₂CH(NH₂)COOR₃ or    —CH₂—S—CH₂CH(NH₂)COOR₃ or

or derivatives thereof or —C═S(NH₂) as additional chelating group.

According to the present invention, the picolylamine resins can beobtained both in a heterodisperse particle size distribution and in amonodisperse particle size distribution.

The preparation of heterodisperse, crosslinked base polymers accordingto process step a) can be carried out by known methods of suspensionpolymerization; see Ullmann's Encyclopedia of Industrial Chemistry, 5thEd., Vol. A, 363-373, VCH Verlagsgesellschaft mbH, Weinheim, 1992. Thewater-insoluble monomer/crosslinker mixture is added to an aqueous phasewhich preferably contains at least one protective colloid to stabilizethe monomer/crosslinker droplets in the disperse phase and the beadpolymers formed therefrom.

A monodisperse, crosslinked bead polymer is, according to the presentinvention, obtained in process step a) by carrying out the reaction ofprocess step a) by the jetting process and/or by the seed/feed process.Both processes are known to those skilled in the art, which will bediscussed in more detail below. According to the invention, amonodisperse particle size distribution of the picolylamine resins ofthe invention is preferably sought.

In an alternative embodiment, step d) can be carried out before step c).

In process step a), at least one monovinylaromatic compound and at leastone polyvinylaromatic compound and/or a (meth)acrylic compound is used.However, it is also possible to use mixtures of two or moremonovinylaromatic compounds and mixtures of two or morepolyvinylaromatic compounds.

In process step a) according to the present invention, preference isgiven to using monoethylenically unsaturated compounds, particularlypreferably styrene, vinyltoluene, ethylstyrene, α-methylstyrene,chlorostyrene, chloromethylstyrene, as monovinylaromatic compounds.Particular preference is given to using styrene or mixtures of styrenewith the abovementioned monomers.

Preferred polyvinylaromatic compounds which act as crosslinker forprocess step a) according to the present invention are multifunctionalethylenically unsaturated compounds, particularly preferably butadiene,isoprene, divinylbenzene, divinyltoluene, trivinylbenzene,divinylnaphthalene, trivinylnaphthalene, divinylcyclohexane,trivinylcyclohexane, triallyl cyanurate, triallylamine, 1,7-octadiene,1,5-hexadiene, cyclopentadiene, norbornadiene, diethylene glycol divinylether, triethylene glycol divinyl ether, tetraethylene glycol divinylether, butanediol divinyl ether, ethylene glycol divinyl ether,cyclohexanedimethanol divinyl ether, hexanediol divinyl ether,trimethylolpropane trivinyl ether, ethylene glycol dimethacrylate,trimethylolpropane trimethacrylate or allyl methacrylate. Divinylbenzeneis particularly preferred in many cases. For most applications,commercial divinylbenzene grades which contain ethylvinylbenzene inaddition to the isomers of divinylbenzene are satisfactory.

The polyvinylaromatic compounds are preferably used in amounts of 1-20%by weight, particularly preferably 2-12% by weight, very particularlypreferably 4-10% by weight, based on the monomer or the mixture thereofwith further monomers. The type of polyvinylaromatic compounds(crosslinkers) is selected with a view to the later use of the beadpolymer.

For the purposes of the present invention, (meth)acrylic compounds aremonoethylenically unsaturated compounds, preferablyalkyl(meth)acrylates, (meth)acrylonitriles, (meth)acrylic acid,particularly preferably methyl acrylate, methyl methacrylate andacrylonitrile. For the purposes of the present invention, veryparticular preference is given to using acrylonitrile or methylacrylate.

The (meth)acrylic compounds are preferably used in amounts of from 1 to30% by weight, particularly preferably from 1 to 10% by weight, based onthe sum of all monomers. According to the invention, (meth)acrylic acidrefers both to acrylic acid and to methacrylic acid. This also appliesto the further (meth)acrylic compounds mentioned in the presentinvention.

The base polymers on which the picolylamine resins of the invention arebased are in each case present in a monodisperse bead size distributionafter process step a).

In a preferred embodiment of the present invention, microencapsulatedmonomer droplets are used in process step a); the materials known foruse as complex coacervates, in particular polyesters, natural orsynthetic polyamides, polyurethanes, polyureas, are possible for themicroencapsulation of the monomer droplets.

As natural polyamide, preference is given to using gelatin. This isemployed, in particular, as coacervate and complex coacervate. For thepurposes of the present invention, gelatin-containing complexcoacervates are, in particular, combinations of gelatin with syntheticpolyelectrolytes. Suitable synthetic polyelectrolytes are copolymershaving built-in units, preferably of maleic acid, acrylic acid,methacrylic acid, acrylamide and methacrylamide. Particular preferenceis given to using acrylic acid and acrylamide. Gelatin-containingcapsules can be hardened by means of customary hardeners, preferablyformaldehyde or glutaric dialdehyde. The encapsulation of monomerdroplets by means of gelatin, gelatin-containing coacervates orgelatin-containing complex coacervates is comprehensively described inEP-A 0 046 535. The methods of encapsulation by means of syntheticpolymers are known. A well-suited method is, for example, phaseinterface condensation, in which a reactive component, preferably anisocyanate or an acid chloride, dissolved in the monomer droplet isreacted with a second reactive component, preferably an amine, dissolvedin the aqueous phase.

The optionally microencapsulated monomer droplets contain an initiatoror mixtures of initiators to trigger the polymerization. Suitableinitiators which are preferred for the process of the invention areperoxy compounds, particularly preferably dibenzoyl peroxide, dilauroylperoxide, bis(p-chlorobenzoyl) peroxide, dicyclohexylperoxy dicarbonate,tert-butyl peroctoate, tert-butylperoxy 2-ethylhexanoate,2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane ortert-amylperoxy-2-ethylhexane, and also azo compounds, particularlypreferably 2,2′-azobis(isobutyronitrile) or2,2′-azobis(2-methylisobutyronitrile).

The initiators are preferably employed in amounts of from 0.05 to 2.5%by weight, particularly preferably from 0.1 to 1.5% by weight, based onthe monomer mixture.

In contrast to the heterodisperse particle size distribution known fromthe prior art, the term monodisperse in the present application refersto bead polymers or picolylamine resins having an additional chelatingfunction in which at least 90% by volume or % by mass of the particleshave a diameter which is in the range of the mode of the diameter ±10%of the mode of the diameter.

For example, in the case of a bead polymer having a mode of the diameterof 0.5 mm, at least 90% by volume or % by mass is in a size range from0.45 mm to 0.55 mm; in the case of a material having a mode of thediameter of 0.7 mm, at least 90% by volume or % by mass is in a sizerange from 0.77 mm to 0.63 mm.

A monodisperse, crosslinked, vinylaromatic base polymer as per processstep a) can be prepared by the processes known from the literature. Forexample, said processes are described in U.S. Pat. No. 4,444,961, EP-A 0046 535, U.S. Pat. No. 4,419,245 or WO 93/12167, whose contents arefully incorporated into the present application in respect of processstep a). If process step a) is carried out by the jetting process or theseed/feed process, monodisperse bead polymers and the monodispersepicolylamine resins to be prepared therefrom are obtained according tothe invention.

The terms microporous or gel-type or macroporous have already beencomprehensively described in the specialist literature. Preferred beadpolymers for the purposes of the present invention, prepared by processstep a), have a macroporous structure.

The formation of macroporous bead polymers can be carried out, forexample, by adding inert materials (porogens) to the monomer mixture inthe polymerization. Suitable materials of this type are, in particular,organic substances which dissolve in the monomer but do not readilydissolve or swell the polymer (precipitants for polymers), preferablyaliphatic hydrocarbons (Farbenfabriken Bayer DBP 1045102, 1957; DBP1113570, 1957).

In U.S. Pat. No. 4,382,124, alcohols having from 4 to 10 carbon atoms,for example, are used as porogens for preparing monodisperse,macroporous bead polymers based on styrene/divinylbenzene. Furthermore,this document gives an overview of the methods of preparing macroporousbead polymers. According to the invention, organic solvents which do notreadily dissolve or swell the polymer formed are preferred as porogens.Preference is given to hexane, octane, isooctane, isododecane, methylethyl ketone, butanol or octanol and isomers thereof.

The optionally microencapsulated monomer droplet can also optionallycontain up to 30% by weight (based on the monomer) of crosslinked oruncrosslinked polymer. Preferred polymers are derived from theabovementioned monomers, particularly preferably from styrene.

The average particle size of the optionally encapsulated monomerdroplets is 10-1000 μm, preferably 100-1000 μm. In the preparation ofthe monodisperse bead polymers in process step a), the aqueous phase canoptionally contain a dissolved polymerization inhibitor. Possibleinhibitors for the purposes of the present invention are both inorganicand organic materials. Preferred inorganic inhibitors are nitrogencompounds such as hydroxylamine, hydrazine, sodium nitrite or potassiumnitrite, salts of phosphorous acid, e.g. sodium hydrogenphosphite, andalso sulphur-containing compounds such as sodium dithionite, sodiumthiosulphate, sodium sulphite, sodium bisulphite, sodium thiocyanate orammonium thiocyanate. Preferred organic inhibitors are phenoliccompounds such as hydroquinone, hydroquinone monomethyl ether,resorcinol, catechol, tert-butyl catechol, pyrogallol or condensationproducts of phenols with aldehydes. Further preferred organic inhibitorsare nitrogen-containing compounds such as hydroxylamine derivatives,preferably N,N-diethylhydroxylamine or N-isopropylhydroxylamine, andalso sulphonated or carboxylated N-alkylhydroxylamine orN,N-dialkylhydroxylamine derivatives, hydrazine derivatives, preferablyN,N-hydrazinodiacetic acid, nitroso compounds, preferablyN-nitrosophenylhydroxylamine, N-nitrosophenylhydroxylamine ammonium saltor N-nitrosophenylhydroxylamine aluminium salt. The concentration of theinhibitor is 5-1000 ppm (based on the aqueous phase), preferably 10-500ppm, particularly preferably 10-250 ppm.

The polymerization of the optionally microencapsulated monomer dropletsto form the spherical bead polymer may, as has been mentioned above,optionally be carried out in the presence of one or more protectivecolloids in the aqueous phase. Suitable protective colloids are naturalor synthetic water-soluble polymers, preferably gelatin, starch,polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid,polymethacrylic acid or copolymers of (meth)acrylic acid and(meth)acrylic esters. Cellulose derivatives, in particular celluloseesters and cellulose ethers, e.g. carboxymethylcellulose,methylhydroxyethylcellulose, methylhydroxypropylcellulose andhydroxyethylcellulose, are very well suited. Particular preference isgiven to gelatin. The amount of protective colloids used is generallyfrom 0.05 to 1% by weight based on the aqueous phase, preferably from0.05 to 0.5% by weight.

The polymerization to form the bead polymer in process step a) canoptionally also be carried out in the presence of a buffer system.Preference is given to buffer systems which adjust the pH of the aqueousphase at the beginning of the polymerization to a value in the rangefrom 14 to 6, preferably from 12 to 8. Under these conditions,protective colloids having carboxylic acid groups are entirely or partlypresent as salts. This exerts a favourable influence on the action ofthe protective colloids. Particularly preferred buffer systems containphosphate or borate salts. For the purposes of the invention, the termsphosphate and borate also encompass the condensation products of theortho forms of corresponding acids and salts. The concentration of thephosphate or borate in the aqueous phase is 0.5-500 mmol/l, preferably2.5-100 mmol/l.

The stirring speed in the polymerization is less critical and, incontrast to the conventional bead polymerization, has no influence onthe particle size. Low stirring speeds which are sufficient to keep thesuspended monomer droplets in suspension and aid the removal of the heatof polymerization are employed. Various stirrer types can be used forthis task. Grid stirrers having an axial action are particularlysuitable.

The volume ratio of encapsulated monomer droplets to aqueous phase ispreferably from 1:0.75 to 1:20, particularly preferably from 1:1 to 1:6.

The polymerization temperature in process step a) depends on thedecomposition temperature of the initiator used. It is generally in therange from 50 to 180° C., preferably from 55 to 130° C. Thepolymerization takes from 0.5 hour to a number of hours. A temperatureprogram in which the polymerization is commenced at low temperature,preferably about 60° C., and the reaction temperature is increased asthe polymerization conversion progresses is preferably employed. In thisway, the requirement for a reliable course of the reaction and a highpolymerization conversion, for example, can be met very well. After thepolymerization, the polymer is isolated by customary methods, preferablyby filtration or decantation, and optionally washed.

The crosslinked bead polymer based on monovinylaromatics which isprepared in process step a) is, in contrast to U.S. Pat. No. 4,098,867(chloromethylation process) functionalized with primary amino groups bythe phthalimide process. For this purpose, the amidomethylation reagentis firstly prepared in process step b). For this purpose, phthalimide ora phthalimide derivative is preferably dissolved in a solvent andadmixed with formalin. A bis(phthalimido) ether is subsequently formedtherefrom with elimination of water. The bis(phthalimido) ether can, inan alternative preferred embodiment, be converted into the phthalimidoester. Preferred phthalimide derivatives for the purposes of the presentinvention are phthalimide itself or substituted phthalimides, preferablymethylphthalimide.

As solvents in process step b), preference is given to using inertsolvents which are suitable for swelling the polymer. According to theinvention, particular preference is given to using chlorinatedhydrocarbons, very particularly preferably dichloroethane or methylenechloride, for this purpose.

In process step b), the bead polymer is condensed with phthalimidederivatives. Preference is given to using oleum, sulphuric acid orsulphur trioxide as catalyst.

The phthalimide process to be used according to the invention in processstep b) can, according to U.S. Pat. No. 4,952,608, be carried out asfollows:

Phthalimide and 20-40% strength aqueous formaldehyde solution (molarratio of phthalimide:formaldehyde about 1:1-1.5) are introduced into theswelling agent (amount of swelling agent: about 3-6 parts by weight perpart by weight of phthalimide). The suspension obtained in this way isheated while stirring to temperatures of from 60 to 80° C. and broughtto a pH of 5-6 by addition of 20-50% strength aqueous sodium hydroxidesolution and, if necessary, kept in this range during the reaction byaddition of further sodium hydroxide solution. The pH is determined bymeans of an electrode dipping into the agitated suspension. The end ofthe reaction can clearly be seen from the suspension having beenconverted into a turbid solution. The stirrer is switched off so thatthe phases can separate. The lower, organic phase containing theN-hydroxymethylphthalimide is separated off and dried.

The solution of N-hydroxymethylphthalimide in the swelling agent whichis obtained in this way is either used directly for the amidomethylationof the crosslinked, water-insoluble organic polymer containing aromaticrings or else the N-hydroxymethylphthalimide is firstly converted intobis(phthalimidomethyl)ether or into an ester and the ether or the esteris used for the amidoalkylation reaction. The amidomethylation of theorganic polymers by means of the solution of N-hydroxymethylphthalimide,bis(phthalimidomethyl)ether or the esters of N-hydroxymethylphthalimidein the swelling agents is carried out in a manner known per se, e.g. bythe procedures described in DE-B 22 11 134, 21 61 628, 25 19 244 and 2418 976.

The amidomethylation of the organic polymers may be illustrated by theamidomethylation using bis(phthalimidomethyl)ether (A) and by theamidomethylation using the acetic ester of N-hydroxymethylphthalimide(B):

A. The solution of N-hydroxymethylphthalimide in the swelling agentwhich is obtained in the first process step is admixed with catalyticamounts of sulphuric acid (0.07 mol of H₂SO₄ per mole ofN-hydroxymethylphthalimide), heated while stirring to reflux temperatureand stirred at this temperature until ether formation is complete (thecourse of ether formation is followed chromatographically; the yield ofether is approximately quantitative). Water is removed from the systemby distillation during this reaction. The suspension present after etherformation is complete is cooled to about room temperature and admixedwith the Friedel-Crafts catalyst, e.g. iron(III) chloride, tintetrachloride or preferably sulphur trioxide, intended for theamidomethylation. The polymer to be amidomethylated is introduced intothis mixture (amount of polymer:ratio of mole of aromatic rings presentin the polymer:bis(phthalimidomethyl)ether=1:0.5-4, preferably1:0.75-2.5). The reaction mixture is heated while stirring totemperatures of from 65 to 80° C. and subsequently stirred at thistemperature for 18 hours. After cooling to room temperature, thephthalimidomethylated polymer is separated off from the liquid phase(the swelling agent), taken up in deionized water and freed of adheringswelling agent by azeotropic distillation. The phthalimidomethylatedpolymer is finally hydrolyzed in a known manner, e.g. by alkaline oracid hydrolysis or by reaction with hydrazine and subsequent acidhydrolysis, optionally in the presence of an organic solvent; thisorganic solvent can, for example, be the swelling agent used for theamidomethylation.

B. In the amidomethylation using esters of N-hydroxymethylphthalimide,e.g. the acetic ester, the dried solution of N-hydroxymethylphthalimidein the swelling agent used which is obtained in the first process stepis admixed with the amount of acetic anhydride required for theesterification and heated while stirring at reflux temperature untilester formation is complete (the course of ester formation is monitoredchromatographically; the yield of ester is virtually quantitative).After the esterification is complete, the solution is cooled to from 20to 50° C. and the organic polymer to be amidomethylated is introducedwhile stirring (amount of polymer:ratio of aromatic rings in thepolymer:mole of ester=1:0.5-4, preferably 1:1-2.5). The polymer isswelled in the ester solution for 0.5-2 hours at 50-70° C. Thesuspension is subsequently heated to reflux temperature and admixed withthe intended Friedel-Crafts catalyst, preferably sulphuric acid, andsubsequently stirred at reflux temperature for 20 hours.

The pH range for the formation of N-methylolphthalimide is 4-10,preferably 5-6.5; the formation of N-methylolphthalimide can be carriedout under atmospheric pressure or superatmospheric pressure.

The work-up of the reaction mixture and the hydrolysis of thephthalimidomethylated polymer is carried out as described under A.

The elimination of the phthalic acid radical and thus the setting-freeof the aminomethyl group is carried out in process step c) by treatingthe phthalimidomethylated crosslinked bead polymer from process step b)with aqueous or alcoholic solutions of an alkali metal hydroxide,preferably sodium hydroxide or potassium hydroxide, at temperatures inthe range from 100 to 250° C., preferably 120-190° C. The concentrationof the sodium hydroxide solution is preferably in the range from 10 to50% by weight, particularly preferably in the range from 20 to 40% byweight. This process makes it possible to prepare crosslinked beadpolymers which contain aminoalkyl groups and have a substitution of thearomatic rings of greater than 1.

The aminomethylated bead polymer formed is finally washed free of alkaliwith deionized water (DI water).

In process step c), the picolylamine resins of the invention areprepared by reacting the monodisperse, crosslinked, vinylaromatic beadpolymers containing primary aminoalkyl groups from process step b) inaqueous suspension with optionally substituted chloromethyl nitrogenheterocycles, preferably chloromethylpyridine or its hydrochloride,2-chloromethylquinoline or 2-chloromethylpiperidine.

Chloromethylpyridine or its hydrochloride can be used as2-chloromethylpyridine, 3-chloromethylpyridine or4-chloromethylpyridine.

As preferred reagent in process step c), use is made of2-chloromethylpyridine hydrochloride, preferably in aqueous solution.

In a preferred embodiment, the reaction in process step c) is carriedout with addition of alkali metal hydroxide solution, particularlypreferably potassium hydroxide solution or sodium hydroxide solution,very particularly preferably sodium hydroxide solution. Addition ofalkali metal hydroxide solution in the reaction of the crosslinked,vinylaromatic base polymer containing aminomethyl groups from processstep c) in aqueous suspension with halomethyl nitrogen heterocycles,preferably picolyl chloride or its hydrochloride, keeps the pH duringthe reaction in the range 4-11. The pH is preferably kept in the range6-8.

In process step d), the second chelating group, viz. the

-   —CH₂P(O)(OR₃)₂ or —CH₂—S—CH₂COOR₃ or —CH₂—S—C₁-C₄-alkyl or    —CH₂—S—CH₂CH(NH₂)COOR₃ or —CH₂—S—CH₂—CH(OH)—CH₂(OH) or

or its derivatives or —C═S(NH₂) group, is introduced.

For this purpose, the bead polymer from process step c) is introduced atroom temperature into aqueous sulphuric acid.

The pH of the suspension is less than 3, preferably less than 2.

Phosphorus-hydrogen-acid compounds, preferably phosphorus(III)compounds, particularly preferably phosphorous acid or dimethylphosphite, or else sulphur-hydrogen-acid compounds, preferablythiohydrogen compounds, particularly preferably thioglycolic acid, alkylmercaptans, particularly preferably butanethiol, L-cystein or1,2-dihydroxypropylmercaptohydrogen, or else C—H-acidic hydroxyquinonederivatives are introduced for this purpose. Finally, aqueous formalinsolution is introduced at temperatures above 50° C., particularlypreferably at from 80 to 95° C.

The mixture is subsequently stirred at reflux temperature for a numberof hours.

After cooling the suspension, the picolylamine resin of the invention isseparated off, preferably by means of a sieve, and washed with water. Toremove relatively small particles of solid and liquid impurities, thepicolylamine resin of the invention can be classified using water in acolumn.

If a group containing an acid function has been introduced as secondchelating group, the picolylamine resin of the invention can beconverted into the salt form by treatment with aqueous alkalis such assodium hydroxide or potassium hydroxide.

The picolylamine resins prepared according to the invention are suitablefor the adsorption of metals, in particular heavy metals and noblemetals, and compounds thereof from aqueous solutions, organic liquids orgases, preferably from acidic, aqueous solutions. The picolylamineresins prepared according to the invention are particularly suitable forthe removal of heavy metals or noble metals from aqueous solutions, inparticular from aqueous solutions of alkaline earth metals or alkalimetals, from brines for alkali metal chloride electrolysis, from aqueoushydrochloric acids, from wastewater or flue scrubbing liquors, but alsofrom liquid or gaseous hydrocarbons, carboxylic acids such as adipicacid, glutaric acid or succinic acid, natural gas, natural gascondensates, petroleum or halogenated hydrocarbons such as chlorinatedor fluorinated hydrocarbons or chlorofluorocarbons. In addition, thepicolylamine resins of the invention are suitable for the removal ofalkaline earth metals from brines as are customarily used in alkalimetal chloride electrolysis. The picolylamine resins of the inventionare also suitable for the removal of heavy metals, in particular iron,cadmium or lead, from materials which are reacted in an electrolytictreatment, for example a dimerization of acrylonitrile to adiponitrile.

The picolylamine resins of the invention are very particularly suitablefor the removal of mercury, iron, cobalt, nickel, copper, zinc, lead,cadmium, manganese, uranium, vanadium, elements of the platinum groupand also gold or silver from the abovementioned solutions, liquids orgases.

In particular, the picolylamine resins of the invention are suitable forthe removal of rhodium or elements of the platinum group and also gold,silver or rhodium or catalyst residues containing noble metal fromorganic solutions or solvents.

However, the picolylamine resins of the invention are very particularlysuitable for the isolation or winning of copper from copper solutionswhich additionally likewise contain divalent foreign metals present inaqueous solution, most particularly preferably for the adsorption ofcopper from copper/iron sulphate solutions or from copper/nickelsulphate solutions.

Apart from the use in metallurgy for the winning of metals of value, thepicolylamine resins of the invention having a tertiary nitrogen atom inthe functional group of the general formula (I) are highly suitable forvarious applications in the chemical industry, the electronics industry,the waste disposal/recycling industry or electroplating or surfacetechnology.

Methods of Examination

Determination of the Amount of Basic Aminomethyl Groups in theAminomethylated, Crosslinked Polystyrene Bead Polymer:

100 ml of the aminomethylated bead polymer are shaken down in a tampingvolumeter and subsequently rinsed into a glass column by means of DIwater. 1000 ml of 2% strength by weight sodium hydroxide solution arefiltered through the polymer over a period of 1 hour and 40 minutes. DIwater is subsequently filtered through until 100 ml of eluate admixedwith phenolphthalein have a consumption of 0.1N (0.1 normal)hydrochloric acid of not more than 0.05 ml.

50 ml of this resin are admixed with 50 ml of DI water and 100 ml of 1Nhydrochloric acid in a glass beaker. The suspension is stirred for 30minutes and subsequently introduced into a glass column. The liquid isdrained off. A further 100 ml of 1N hydrochloric acid are filteredthrough the resin over a period of 20 minutes. 200 ml of methanol aresubsequently filtered through. All eluates are collected and combinedand titrated against methyl orange with 1N sodium hydroxide.

The amount of aminomethyl groups in 1 liter of aminomethylated resin iscalculated by the following formula: (200−V)·20=mol of aminomethylgroups per liter of resin.

DI water or deionized water is, for the purpose of the presentinvention, characterized by having a conductivity of from 0.1 to 10 μS,with the content of dissolved or undissolved metal ions being notgreater than 1 ppm, preferably not greater than 0.5 ppm, for Fe, Co, Ni,Mo, Cr, Cu as individual components and not greater than 10 ppm,preferably not greater than 1 ppm, for the sum of the metals mentioned.

The present invention has been described with reference to specificdetails of particular embodiments thereof. It is not intended that suchdetails be regarded as limitations upon the scope of the inventionexcept insofar as and to the extent that they are included in theaccompanying claims.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise.

EXAMPLE 1

1a) Preparation of a Monodisperse, Macroporous Bead Polymer Based onStyrene, Divinylbenzene and Ethyl Styrene

3000 g of DI water were placed in a 101 glass reactor and a solution of10 g of gelatin, 16 g of disodium hydrogenphosphate dodecahydrate and0.73 g of resorcinol in 320 g of DI water was added and the mixture wasmixed. The mixture was heated to 25° C. While stirring, a mixture of3200 g of microencapsulated monomer droplets having a narrow particlesize distribution and composed of 3.6% by weight of divinylbenzene and0.9% by weight of ethylstyrene (used as commercial isomer mixture ofdivinylbenzene and ethylstyrene containing 80% of divinylbenzene), 0.5%by weight of dibenzoyl peroxide, 56.2% by weight of styrene and 38.8% byweight of isododecane (industrial isomer mixture having a highproportion of pentamethylheptane) was subsequently added, where themicrocapsule consisted of a formaldehyde-cured complex coacervate ofgelatin and a copolymer of acrylamide and acrylic acid, and added to3200 g of aqueous phase having a pH of 12. The average particle size ofthe monomer droplets was 300 μm.

The mixture was fully polymerized while stirring by increasing thetemperature according to a temperature program commencing at 25° C. andending at 95° C. The mixture was cooled, washed on a 32 μm sieve andsubsequently dried at 80° C. under reduced pressure. This gave 1893 g ofa spherical bead polymer having an average particle size of 280 μm, anarrow particle size distribution and a smooth surface.

The bead polymer had a chalky white appearance and had a bulk density ofabout 370 g/l.

1b) Preparation of an Amidomethylated Bead Polymer

1455 ml of dichloroethane, 540.7 g of phthalimide and 373.7 g of 30.1%strength by weight formalin were placed in a reaction vessel at roomtemperature. The pH of the suspension was set to 5.5-6 by means ofsodium hydroxide solution. The water was subsequently removed bydistillation. 36.9 g of sulphuric acid were then added. The water formedwas removed by distillation. The mixture was cooled. At 30° C., 144.9 gof 65% strength oleum and subsequently 371.4 g of monodisperse beadpolymer prepared according to process step 1a) were introduced. Thesuspension was heated to 70° C. and stirred at this temperature for afurther 6.5 hours. The reaction liquor was taken off, DI water wasintroduced and residual amounts of dichloroethane were removed bydistillation.

Yield of amidomethylated bead polymer: 1860 ml

Elemental analytical composition:

-   Carbon: 76.8% by weight;-   Hydrogen: 5.2% by weight;-   Nitrogen: 5.0% by weight;-   Balance: oxygen.    1b′) Preparation of an Aminomethylated Bead Polymer

512 ml of 50% strength by weight sodium hydroxide solution and 1638 mlof DI water were introduced at room temperature into 1800 ml ofamidomethylated bead polymer from 1b). The suspension was heated to 180°C. over a period of 2 hours and stirred at this temperature for 8 hours.The bead polymer obtained was washed with DI water.

Yield of aminomethylated bead polymer: 1440 ml

Elemental analytical composition:

-   Nitrogen: 9.3% by weight;-   Carbon: 78.5% by weight;-   Hydrogen: 8.5% by weight.

Determination of the amount of basic groups: 2.16 mol/liter of resin

1c) Preparation of a Resin Having Monopicolylamine Groups

Apparatus:

6 liter reactor, stirrer, pH electrode, sodium hydroxide metering,reflux condenser, heating bath 1000 ml of DI water and 1500 ml of resinfrom step 1c) were placed in a reaction vessel.

The suspension was heated to 90° C. At this temperature, 639.6 gram ofpicolyl chloride hydrochloride solution (519.47 g of 98.5% pure picolylchloride hydrochloride+120.13 g of water) was introduced over a periodof 4 hours.

The pH was maintained at pH 7.0 by introduction of aqueous 50% strengthby weight sodium hydroxide solution.

The mixture was subsequently heated to 95° C. and stirred at pH 7.0 fora further 6 hours.

Consumption of 50% strength by weight sodium hydroxide solution: 553 g

The mixture was cooled. The resin was poured onto a sieve and washedwith water.

Yield: 1900 ml

The mass of resin was introduced into a column and treated with 1000 mlof 4% strength by weight sodium hydroxide solution.

Yield: 1900 ml

Elemental analytical composition:

-   C, 80.0% by weight-   N, 11.5% by weight-   H, 7.4% by weight-   O, 2.6% by weight-   HCl number: 2.25 mol/l-   Volume of form as supplied: 100 ml-   Volume of chloride form: 138 ml-   Dry weight: 50 ml, 17.06 g    1d) Preparation of a Bifunctional, Monodisperse Resin Having    Picolylamine Groups and Methylphosphonic Acid Groups    Apparatus:

3 liter reactor, stirrer, pH electrode, sodium hydroxide metering,reflux condenser, heating bath

260 ml of DI water and 500 ml of resin from Example 1c) were placed in areaction vessel at room temperature. 149 gram of dimethyl phosphite wereintroduced at 25° C. while stirring over a period of 15 minutes. Themixture was stirred for a further 30 minutes. The suspension was heatedto 60° C. 882 gram of sulphuric acid monohydrate were introduced over aperiod of 4 hours. The mixture was heated to reflux temperature and 259gram of 30% strength by weight formalin solution were introduced at thistemperature over a period of 1 hour.

The mixture was stirred at reflux temperature for a further 6 hours.After cooling, the resin was filtered off on a sieve and washed with DIwater.

The resin was rinsed into a glass column by means of DI water andclassified.

Yield: 725 ml

The resin was transferred to a glass column. 2000 ml of 4% strength byweight aqueous sodium hydroxide solution were introduced into the columnfrom above over a period of 2 hours. The resin was subsequently washedwith 2000 ml of DI water.

-   Yield: 815 ml-   Amount of methylphosphonic acid groups: 1.54 mol/l-   Volume of form as supplied: 100 ml-   Volume of 1st H form: 81 ml-   Volume of Na form: 105 ml-   Volume of 2nd H form: 81 ml

Further examples of picolylamine resins according to the inventionhaving the structural unit of the formula (I)

(I)

Ex. m R₂ R₁ 2 2 —CH₂P(O)(OR₃)₂

3 3 —CH₂P(O)(OR₃)₂

4 4 —CH₂P(O)(OR₃)₂

5 1 —CH₂—S—CH₂COOR₃

6 2 —CH₂—S—CH₂COOR₃

7 3 —CH₂—S—CH₂COOR₃

8 4 —CH₂—S—CH₂COOR₃

9 1 —CH₂—S—C₁-C₄-alkyl

10 2 —CH₂—S—C₁-C₄-alkyl

11 3 —CH₂—S—C₁-C₄-alkyl

12 4 —CH₂—S—C₁-C₄-alkyl

13 1 —CH₂—S—H₂CH(NH₂)COOR₃

14 2 —CH₂—S—H₂CH(NH₂)COOR₃

15 3 —CH₂—S—H₂CH(NH₂)COOR₃

16 4 —CH₂—S—H₂CH(NH₂)COOR₃

17 1 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

18 2 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

19 3 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

20 4 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

21 1

22 2

23 3

24 4

25 1 —C═S(NH₂)

26 2 —C═S(NH₂)

27 3 —C═S(NH₂)

28 4 —C═S(NH₂)

29 1 —CH₂P(O)(OR₃)₂

30 1 —C═S(NH₂)

31 1

32 1 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

33 1 —CH₂—S—C₁-C₄-alkyl

34 1 —CH₂—S—CH₂COOR₃

35 2 —CH₂—S—CH₂COOR₃

36 2 —CH₂P(O)(OR₃)₂

37 2 —C═S(NH₂)

38 3 —CH₂P(O)(OR₃)₂

39 4 —CH₂P(O)(OR₃)₂

40 3 —CH₂—S—CH₂COOR₃

41 4 —CH₂—S—CH₂COOR₃

42 3 —C═S(NH₂)

43 4 —C═S(NH₂)

44 3

45 4

46 1 —CH₂P(O)(OR₃)₂

47 2 —CH₂P(O)(OR₃)₂

48 3 —CH₂P(O)(OR₃)₂

49 4 —CH₂P(O)(OR₃)₂

50 4 —CH₂—S—CH₂COOR₃

51 1 —CH₂—S—CH₂COOR₃

52 2 —CH₂—S—CH₂COOR₃

53 3 —CH₂—S—CH₂COOR₃

54 4 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

55 1 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

56 2 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

57 3 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

58 1

59 2

60 3

61 4

62 2

63 1

64 3

65 4

66 1 —CH₂—S—CH₂—CH(OH)—CH₂(OH

67 2 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

68 3 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

69 4 —CH₂—S—CH₂—CH(OH)—CH₂(OH)

70 1 —CH₂—S—CH₂COOR₃

71 2 —CH₂—S—CH₂COOR₃

72 3 —CH₂—S—CH₂COOR₃

73 4 —CH₂—S—CH₂COOR₃

74 2 —CH₂P(O)(OR₃)₂

75 3 —CH₂P(O)(OR₃)₂

76 1 —CH₂P(O)(OR₃)₂

77 4 —CH₂P(O)(OR₃)₂

78 3 —C═S(NH₂)

79 4 —C═S(NH₂)

80 1 —C═S(NH₂)

81 1 —C═S(NH₂)

82 1 —CH₂—S—C₁-C₄-alkyl

83 2 —CH₂—S—C₁-C₄-alkyl

84 3 —CH₂—S—C₁-C₄-alkyl

85 4 —CH₂—S—C₁-C₄-alkyl

What is claimed is:
 1. A picolylamine resin, comprising: thecopolymerization product of at least one monovinylaromatic compound andat least one polyvinylaromatic compound, wherein said picolylamine resincomprises, as functional groups, tertiary nitrogen atoms in structuresaccording to the general formula (I)

where R₁ is an optionally substituted picolyl, R₂ is —CH₂P(O)(OR₃)₂ R₃is a radical from the group consisting of H, Na and K, m is an integerfrom 1 to 4, n and p are each, independently of one another, a number inthe range from 0.1 to 1.9 and the sum of n and p is 2, and M is thepolymer matrix.
 2. The picolylamine resin according to claim 1, whereinthe resin has a macroporous structure.
 3. The picolylamine resinaccording to claim 1, wherein the monovinylaromatic compound is styreneand the polyvinylaromatic compound is divinylbenzene.
 4. Thepicolylamine resin according to claim 1, wherein n is a number from 0.5to 1.5 and p is a number from 1.5 to 0.5 and the sum of n plus p is 2.5. The picolylamine resin according to claim 1, wherein saidpicolylamine resin has a monodisperse particle size distribution.
 6. Aprocess for the adsorption of a metal from an aqueous solution, anorganic liquid and/or a gas, comprising: contacting the aqueoussolution, organic liquid and/or gas containing said metal with thepicolylamine resin according to claim
 1. 7. The process according toclaim 6, wherein the metal is selected from the group consisting ofmercury, iron, cobalt, nickel, copper, zinc, lead, cadmium, manganese,uranium, vanadium, elements of the platinum group, gold, and silver. 8.A process for the adsorption of copper from a sulphate solution or acopper/nickel sulphate solution containing said copper, comprising:contacting the sulphate solution or the copper/nickel sulphate solutionwith the picolylamine resin according to claim
 1. 9. A process forpreparing the picolylamine resin according to claim 1, comprising: a)reacting monomer droplets of a mixture of a monovinylaromatic compound,a polyvinylaromatic compound, an initiator or an initiator combination,thereby, forming a crosslinked bead polymer, b) functionalizing thecrosslinked bead polymer with primary amino groups, thereby, forming afirst functionalized bead polymer, c) reacting the first functionalizedbead polymer with halomethyl nitrogen heterocycles to, thereby, formsecond functionalized bead polymers, said second functionalized beadpolymers comprising basic anion-exchanging groups and methyl nitrogenheterocycles, and d) reacting said second functionalized bead polymerwith phosphorus-hydrogen-acidic compounds to, thereby, form thepicolylamine resin.
 10. The picolylamine resin according to claim 1,wherein the resin has a gel-type structure.
 11. The picolylamine resinaccording to claim 1, wherein the copolymerization product furthercomprises the product of at least one (meth)acrylic compound.
 12. Theprocess according to claim 9, wherein the mixture of step a) furthercomprises monomer droplets of a (meth)acrylic compound.